Prevalence and risk factors for bruises in Chilean bovine carcasses

Records of cattle slaughtered at two Chilean slaughterhouses (SLH1 and SLH2) were used to determine prevalence and risk factors for carcasses with bruises. Bruise prevalence amounted to 12.3% but differed between slaughterhouses (20.8% for SLH1 and 8.6% for SLH2 respectively). Bruise severity grade 1 (mild) was most frequently recorded. The type of the animal, source of animal, the level of fat cover and lairage time were associated with the presence of bruises. Older categories of animals and animals that pass through a market before being moved to the slaughterhouse are more prone to show bruises. The results also indicate that under the reported Chilean circumstances animals that have longer lairage times (over 12 h) have a significantly reduced risk for bruises, except for oxen. Presence of bruises is also significantly associated with increased carcass pH values.     

Ligand Binding Promiscuity of Human Liver Fatty Acid Binding Protein: Structural and Dynamic Insights from an Interaction Study with Glycocholate and Oleate

Human liver fatty acid binding protein (hL‐FABP) has been reported to act as an intracellular shuttle of lipid molecules, thus playing a central role in systemic metabolic homeostasis. The involvement of hL‐FABP in the transport of bile salts has been postulated but scarcely investigated. Here we describe a thorough NMR investigation of glycocholate (GCA) binding to hL‐FABP. The protein molecule bound a single molecule of GCA, in contrast to the 1:2 stoichiometry observed with fatty acids. GCA was found to occupy the large internal cavity of hL‐FABP, without requiring major conformational rearrangement of the protein backbone; rather, this led to increased stability, similar to that estimated for the hL‐FABP:oleate complex. Fast‐timescale dynamics appeared not to be significantly perturbed in the presence of ligands. Slow motions (unlike for other proteins of the family) were retained or enhanced upon binding, consistent with a requirement for structural plasticity for promiscuous recognition.     

Studies of the copolymerisation of acrylic acid with n‐butyl vinyl ether

BACKGROUND: Copolymers of acrylic acid (AA) are important materials for the preparation of glass ionomer cements. Copolymerisation of AA is widely used to alter the acid strength of the material and to increase the number of salt bridges formed in cements. In this paper we report the copolymerisation of AA with n‐butyl vinyl ether (BVE) to form unique copolymers of the hemiacetal ester and with BVE incorporated into the main chain. RESULTS: AA and BVE undergo a spontaneous reaction to form a hemiacetal ester which can itself undergo free radical copolymerisation. The kinetics of this reaction in the bulk state have been examined. In addition, under these conditions BVE is incorporated into the polymer main chain via a free radical mechanism. CONCLUSION: Novel copolymers of the hemiacetal ester and BVE have been prepared in this study. The hemiacetal side chains are labile under moderate heating, being converted back to the acid analogue. Copyright © 2009 Society of Chemical Industry     

Financial econometric analysis at ultra-high frequency: Data handling concerns

Data collection at ultra high-frequency on financial markets requires the manipulation of complex databases, and possibly the correction of errors present in the data. The New York Stock Exchange is chosen to provide evidence of problems affecting ultra high-frequency data sets. Standard filters can be applied to remove bad records from the trades and quotes data. A method for outlier detection is proposed to remove data which do not correspond to plausible market activity. Several methods of aggregation of the data are suggested, according to which corresponding time series of interest for econometric analysis can be constructed. As an example of the relevance of the procedure, the autoregressive conditional duration model is estimated on price durations. Failure to purge the data from “wrong” ticks is likely to shorten the financial durations between substantial price movements and to alter the autocorrelation profile of the series. The estimated coefficients and overall model diagnostics are considerably altered in the absence of appropriate steps in data cleaning. Overall the difference in the coefficients is bigger between the dirty series and the clean series than among series filtered with different algorithms.     

Overdependence on degraded gist memory in Alzheimer's disease.

Alzheimer's disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determinant spreading associated with demyelination in a nonhuman primate model of multiple sclerosis

Definition of the immune process that causes demyelination in multiple sclerosis is essential to determine the feasibility of Ag-directed immunotherapy. Using the nonhuman primate, Callithrix jacchus jacchus (common marmoset), we show that immunization with myelin basic protein and proteolipid protein determinants results in clinical disease with significant demyelination. Demyelination was associated with spreading to myelin oligodendrocyte glycoprotein (MOG) determinants that generated anti-MOG serum Abs and Ig deposition in central nervous system white matter lesions. These data associate intermolecular "determinant spreading" with clinical autoimmune disease in primates and raise important issues for the pathogenesis and treatment of multiple sclerosis.     

Long-term expression and secretion of human glucocerebrosidase by primary murine and human myoblasts and differentiated myotubes

The majority of studies dealing with DNA analyses are made on fixed cells. In this context, the efficiency as fixatives of ethanol, methanol, acetone, Carnoy, Boehm-Sprenger and aldehydes was determined using two different DNA fluorescent probes, Hoechst 33342 and propidium iodide. The purpose of our study was to find the fixative that would provide the best results with respect to the following parameters: aggregates, cell size and granularity, and DNA staining analysis. Using murine fibroblasts, we found that 68% ethanol, 85% methanol and aldehydes did not increase aggregate formation, whereas Carnoy, acetone or Boehm-Sprenger fixatives did. The results show that aldehydes seem to alter cell size least. All fixatives induce an increase in cell granularity, which is very pronounced with alcohols, but aldehydes alter morphology less than alcohols. We observed that the fixatives giving the best resolution with Hoechst 33342 staining lead to a lower measurement variability than with propidium iodide staining. This study leads us to conclude that 68% ethanol and 85% methanol can be considered as appropriate fixatives for flow cytometry studies of DNA content.     

Association of glyceraldehyde-3-phosphate dehydrogenase expression with cell motility and metastatic potential of rat prostatic adenocarcinoma

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression is increased in Dunning R-3327 rat prostatic adenocarcinoma cell lines relative to normal rat ventral prostate tissue. GAPDH expression closely correlates with cell motility of Dunning prostate cancer cell lines and accurately distinguishes cell lines with high metastatic potential from those with low metastatic potential. Increased GAPDH expression in the cancer cell lines is not simply related to increased growth rate, since rapidly proliferating normal prostate tissue did not exhibit elevated GAPDH expression.     

Long-term T cell memory requires the surface expression of self-peptide/major histocompatibility complex molecules

How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo. Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-dependent expression of self-peptide/major histocompatibility complex class I molecules in recipient animals. Therefore, it appears that the level of T cell receptor engagement provided by transporter of antigen protein 1-dependent, self-peptide/major histocompatibility complexes is sufficient to maintain the long-term survival and functional phenotype of memory cells in the absence of persistent antigen. These data suggest that positive selection plays a role not only in T cell development but also in the maintenance of T cell memory.